Cemetery Creek canyon / Moraga Canyon

The valley of Glen Echo Creek, “Mountain View Valley,” is much larger than the current creek has the power to excavate. This is especially apparent at its head end, above Mountain View Cemetery where the creek is also known as Cemetery Creek. In this view (click it for a larger version), the valley is a steep-sided, tree-filled dogleg, almost a gorge, with homes perched high above a landfilled floor and Moraga Avenue running through it. I think of it as Cemetery Creek Canyon. The Google map below gives a feeling of how odd the canyon is, almost a box canyon with no sizeable watershed to feed it.

UPDATE: By the way, a story in the paper referred to this as Moraga Canyon, so I should probably call it that too, even though Moraga itself is way over the mountain. Once upon a time, Moraga Road did go to Moraga.

I wonder if, like Dimond Canyon, there is an explanation that involves a beheaded watershed from movement on the Hayward fault. The rock at the valley head, above the narrowest spot at Maxwellton Road, is Franciscan mélange, which is not an especially rigid rock. A bit of compression across the fault might squeeze it up, like clay in the hand. I don’t have a way to test this hypothesis, with rock exposures so scarce there, but the idea tickles me every time I look here.

Advertisements

Share

Like this:

LikeLoading...

Related

This entry was posted on 18 August 2009 at 10:03 pm and is filed under Oakland geology puzzles. You can follow any responses to this entry through the RSS 2.0 feed.
You can skip to the end and leave a response. Pinging is currently not allowed.